Means for cooling chain grates



March 31, 1931. B. H. MILLE1 ETAL 1,798,747

MEANS FOR COOLING CHAIN GRATES Filed May 25, 1928 2 Sheets-Shet l wwiw 'i M W ATTORNEYS March 31, 1931. s. H. MILLER ETAL 1,793,747

MEANS FOR 000mm CHAIN GRATES Filed May 26, 1928 2 Sheets-Sheet 2 ATTORN EY5 Patented Mar. 31, 1931 UNITED STATES PATENT OFFICE BENJAMIN H. MILLER, 01' WADSWORTH, AND RICHARD M. GIVEN, OF BARBERTON,

OHIO, ASSIGNORS TO THE BABCOCK & WILCOX COMPANY, OF BAYONNE, NEW

JERSEY, A. CORPORATION OF NEW JERSEY MEANS FOR COOLING CHAIN GRATES Application filed May 26,

This invention relates to a novel and i1nproved means for cooling the lower run of a chain grate, and will be best understood from the following description when read in connection with the accompanying drawings.

In those drawings, in which we have shown a selected embodiment of the invention,

Fig. l is a sectional view through the lower part of a furnace having our invention embodied therein.

Figs. 2, 3, 4, and 6, are sections on the lines 2-2, 3-3, H, 5-5 and 6-6 of Fig. 1.

Referring particularly to Fig. 1, we have shown our invention as applied to a chain grate stoker disposed in the lower part of a furnace whose combustion chamber is indicated by the numeral 1, and which comprises the combustion arch 2 beneath which fuel is carried by the chain grate 3. Coal is fed to the grate from a hopper i disposed in front of the furnace, and the grate carries the coal in a moving bed to the rear of the furnace, the grate being operated by the usual sprocket wheels 5. The above described apparatus in itself forms no part of the invention, and

the details of its construction have been omitted.

The lower run 6 of the chain grate is supported upon a drag plate 7 which comprises a plurality of plates or sections extending lengthwise of the grate and having their edges united by suitable joints indlca-ted at 8. Beneath the joints 8 or adjacent thereto, are supporting members 9 which also extend lengthwise of the grate as best shown in Fig. 2. Intermediate the members 9 may be arranged other supporting members 10.

Secured to the members 9 and 10, are plates 11 which form the bottom of channels through which water may be conducted as will be described presently. The members 9 and 10 may be secured to the plates 7 and 11 by welding or by other suitable means. The entire set of channels formed by the plates 3 11 and the members 9, may be supported by transversely extending beams 12.

As best shown in Fig. 2, each of the channels for conducting water is supplied near its opposite ends with an inlet and an outlet, the

' inlet being shown at 13 and the outlet at 14.

1928. Serial No. 280,693.

As shown in Figs. 1 and 6, the outlet has a i A.

vertically extending ring 15 disposed within the channelto limit the level of water flowing therethrough. Also, adjacent the ends of each channel are an inlet and an outlet for air, the inlet being indicated at 16 and the outlet at 17, and it will be seen that they are so arranged with respect to the inlets and outlets for water, that the flow of air through each channel will be in a direction counter to the flow of water. As best shown in Figs. 1 and 3, both the inlet and outlet for air are provided with an upwardly extending ring 18 within the channels so as to prevent water from flowing over into these air inlets and outlets. The rings 18 are of course higher than the rings 15, the latter limiting the height of the water to an elevation lower than that of the top edges of the rings 18. Suction is provided by a fan 19 which is connected to a cross or manifold duct 20 which in turn is connected to each of the outlets 17. Beneath the front end of the grate is a siftings hopper 21 in which water 22 may be placed, and into which may be dropped siftings which work through the upper run of the grate, and are carried by the lower run along the drag plate 7 When the grate is used with a forced draft passing into the space between the upper and lower runs and thus upward through the upper run as is common, the siftings carried by the lower grate may sometimes be blown outwardly into the boiler room from the front end of the grate. To obviate this difficulty, we provide a branch duct 23 through the rear wall of the hopper and connecting with the duct 20. The fan 19 may thus be used as a suction means to draw thedust and fine ashes in the siftings into the duct 20 instead of permitting them to pass out into the boiler room. The air from the fan may be discharged through the pipe 24 and may be used or wasted as desired. For example, it may be used as combustion air, or for any other purpose for which heated air may be usefully employed. The amount of suction in the duct 23 may be governed by a suitable damper 25 and the amount of suction in the channels ing the speed of the fan 19. Furthermore, the rate of flow of water through the channels may be controlled by a suitable valve 26 in the inlet pipe.

In operation, water and air may pass through the channels beneath the drag plates in opposite directions, as described above. The heat is partially conducted from the supporting members, which are illustrated as channel sections, to the water, and the air conducts some of the heat from the water and also directly from the steel members with which it comes in contact, that is from the bottom of the drag plate, and from the supporting members forming the sides of the channels. It will be seen that the water enters each channel at a point near the hotter end of the grate, while theair enters adjacent the other or cooler end, and therefore a Substantially uniform temperature will be achieved beneath the lower run.v

The supporting members are of relatively large cross-section, so as to readily conduct heat to the water and the heat will also be conducted by the supporting members and by the plates 11 to the air contacting with the under side of the. plates, 11.

We claim 1. In a furnace having a chain grate stoker, means to support the lower run of said stoker, means to circulate water beneath said sup porting means, a member in thermal contact with both the water and said supporting means and adapted to conduct heat from the supporting means to the water, and means to circulate air in thermal contact with said Water.

2., In a furnace having a chain grate stoker, a drag plate supporting the lower run of said stoker, and means to circulate water he neath said plate, and a member in thermal contact with both the plate and the water and adapted to conduct heat from the plate to the water.

8. In a furnace having a chain grate stoker, a drag plate supporting the lower run of said stoker, meansforming a channel extending lengthwise of said dragplate and beneath the same, means for passing water through said channel, and means for passing air through the same channel above the water.

4c. In a furnace having a chain grate stoker. a drag plate supporting the lower run of said stolzer, means forming a channel extending lengthwise of'said drag plate and beneath the same, means. for passing water through said channel in one direction, and means for passing air through the same channel above the water in the opposite direction.

5. In a furnace having a chain grate stoker, a drag plate supporting the lower run of said stolzer, means forming a channel extending lengthwise of said drag-plate and beneath the same, means for passing water through,

said channel, means for passing air through the same channel above the water, and means for controlling the flow of said water.

6. In a furnace having a chain grate stoker, a drag plate supporting the lower run of said Stoker, means forming a channel extending lengthwise of said drag plate and beneath the same, means for passing water through said channel, means for passing air-throughthe same channel above the water, and means for controlling thetiow of said air.

7. In a furnace having a chain grate stoker, a dra plate supporting the lower run of said stoker and formed in a plurality of sections extending longitudinally of the stoker, a support extending longitudinally of the stoker and adapted to support adjacent edges of said sections, said supports forming the sides of channels beneath said sections, plates secured to said supports and disposed beneath the same and forming the bottoms of said channels, an inlet and an outlet for water adjacent opposite ends of each channel, and an inlet, and an outlet for air also adjacent opposite ends of each channel.

8. In a furnace having a chain grate stoker,

a drag plate supporting the lower run of said stolrer, means forming a channel extending lengthwise of said drag plate and beneath the same, an inlet and an outlet for water adinlet and an outlet for air also adjacent opposite ends ofsaid channel.

9. In a furnace having a chain grate stoker, a drag plate supporting the lower run of said stoker, means forming a channel extend ing lengthwise of said drag plate and beneath the same, an inlet and an outlet for water adjacent opposite ends of said channel, and an inlet and an outlet for air also adjacent op posite ends of said channel, said inlets and outlets extending through the bottoms of said channels, and upwardly extending rings surrounding the air inlet and outlet.

10. In 'a furnace having a chain grate stoker, a drag plate supporting the lower run of said stoker, means forming a channel extending lengthwise of said drag plate and beneath the same, an inlet and an outlet for water adjacent opposite endsof said channel, an inlet and an outlet for air also adjacent opposite ends of said channel, said inlets and outlets extending through the bottoms of said channels, and upwardly extending rings surrounding the air inlet and outlet and the water outlet.

BENJAMIN I-I. MILLER. RICHARD M. GIVEN.

jacent opposite ends of said channel, and an 

